1207.6192 (Li-Jun Lang et al.)

Majorana fermions in density modulated p-wave superconducting wires    [PDF]

Li-Jun Lang, Shu Chen

We study the p-wave superconducting wire with a periodically modulated chemical potential and show that the Majorana edge states are robust against the modulation of density. In some particular regimes, the Majorana fermions are greatly enhanced by the periodic modulation. The existence of Majorana edge fermions in the open chain can be characterized by a topological $Z_2$ invariant of the bulk system, which can be applied to determine the phase boundary between the topologically trivial and nontrivial superconducting phases. We also demonstrate the existence of the zero-energy peak in the spectral function of the topological superconducting phase, which is only sensitive to the open boundary condition but robust against the disorder.

View original: http://arxiv.org/abs/1207.6192